Loblolly pine tree named cf lp1-7696

ABSTRACT

A new and distinctive variety of a loblolly pine tree which has been denominated varietally as ‘CF LP1-7696’ which is distinguished by high growth rate, good resistance to fusiform rust, excellent stem straightness, medium crown width, medium number of whorls, medium branch angle and medium branch diameter.

LATIN NAME

Pinus taeda

VARIETY DENOMINATION ‘CF LP1-7696’ BACKGROUND

A new variety of loblolly pine tree (Pinus taeda), has been discovered. This selection has been designated as ‘CF LP1-7696.’

This new variety is a progeny of two second generation selections. The female parent is a progeny of two first generation selections made in Cherokee County, Tex. and Tyler County, Tex. The male parent is a progeny of an open pollinated first generation selection made in Montgomery County, Tex.

Cross pollination occurred in early 2000 followed by induction and cryopreservation of embryogenic tissue in 2001. First somatic seedlings were produced in 2002 and planted in early 2003 in three field experiments. A total of 30 ramets were planted at 10 ramets per field experiment. The field experiments are located in Texas and Louisiana.

BRIEF SUMMARY

A new and distinct cultivar of loblolly pine (Pinus taeda) is distinctly characterized by high growth rate, good resistance to fusiform rust, excellent stem straightness, medium crown width, medium number of whorls, medium branch angle, medium branch diameter and which is mature for commercial harvesting sooner than conventionally grown trees under the ecological conditions prevailing in the Gulf Coastal Plains of the United States.

The Pinus taeda plants of this variety were asexually propagated using an advanced form of micropropagation called somatic embryogenesis carried out at a production facility in Victoria, Canada. Somatic embryogenesis uses a complex process which relies on the splitting of one embryo into many identical embryos. Somatic embryos can then be grown into plants which are all identical genetically. The asexual propagation occurs at an earlier stage in the plant's life cycle than most other micropropagated plants. The detailed methods for somatic embryogenesis used for asexually propagating conifers in general are described in U.S. Pat. No. 6,372,496 and for loblolly pine in particular in U.S. Patent Application Publication No. 2004/0203150.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are color photographs showing the new variety of loblolly pine.

FIG. 1 is a photograph showing ‘CF LP1-7696’ ramet #3 planted in Beulah, Tex. The picture was taken after five field growing seasons. The picture shows superiority of growth and medium crown width.

FIG. 2 is a photograph showing ‘CF LP1-7696’ ramet #5 planted in Beulah, Tex. The picture was taken after five field growing seasons. The picture shows excellent stem straightness, medium number of whorls per unit stem length, medium angle between the stem and the branches, and medium branch diameter (relative to the size of the stem).

DETAILED BOTANICAL DESCRIPTION

The botanical details of this new and distinct variety of loblolly pine tree follow. All color descriptions are made in reference to The Royal Horticultural Society (R.H.S.) Colour Chart (2005).

-   Parentage: Female parent — (Unknown) progeny of two first generation     selections made in Cherokee County, Tex. and Tyler County, Tex. Male     parent — (Unknown) progeny of an open pollinated first generation     selection made in Montgomery County, Tex. -   Leaf: Evergreen needles, 6 to 9 inches long, with (usually) three     yellow-green needles per fascicle. The color of the foliage was     taken from field established trees aged 6 years, but was not found     to vary significantly with age. The color of the foliage was RHS     137A (60%) and 136A (40%). -   Flower: Monoecious; males long cylindrical, red to yellow, in     clusters at branch tips; females yellow to purple. -   Fruit: Ovoid to cylindrical, 3 to 6 inch red-brown cones; umbo is     armed with a short spine, maturing in early fall. Cones are sporadic     in 5-7 year old plants. -   Branch: Orange-brown in color, fine to moderately stout; buds are     narrowly ovoid, light reddish brown. -   Bark: Initially red- to gray-brown and scaly; older trees are ridged     and furrowed, with somewhat rounded scaly plates; very old trees     have red-brown, flat scaly plates. -   Shape: A medium to large tree can reach well over 100 feet tall,     self-prunes well and develops a fairly straight trunk and an oval,     somewhat open crown. Compared to unimproved loblolly pine trees, ‘CF     LP1-7696’ is characterized by high growth rate, good resistance to     fusiform rust (caused by Cronartium quercuum (Berk.) Miyabe ex     Shirai f. sp. fusiforme (Cumm.) Burds. et Snow), excellent stem     straightness, medium crown width, medium number of whorls, medium     branch angle and medium branch diameter. -   Average height: 20 ft after 5 field growing seasons. -   Maximum height: 24 ft after 5 field growing seasons. -   Average trunk diameter at breast height (4.5 feet above the soil     level): 3.8 inches after 5 field growing seasons and 4.7 inches to     6.0 inches after 6 field growing seasons. -   Sampling of branch characteristics: In order to sample branches from     a consistent position from one tree to the next the following     methodology was utilized. From a point nine feet from the base of     the tree, the first complete whorl of limbs below was labeled “Whorl     One” and the first complete whorl of limbs above labeled “Whorl     Two”. This sampling point was chosen because it is the midpoint of     the basal sixteen foot log of each tree. A complete whorl was     defined as one with at least three branches. All measurements were     taken commencing on the South side of the tree and progressing     anticlockwise around the stem. When more than three branches were     available for measurement on the whorl the largest three branches,     by basal diameter, were used for sampling. The following branch     characteristics were measured after six field growing seasons. -   Branch diameter: Diameter of each measured branch was taken at its     base. Using a caliper the diameter of the branch, over bark, was     measured to the closest 16^(th) of an inch. ‘CF LP1-7696’ has an     average branch diameter of 0.63 inches at the base of the branch.     Zygotic seedlings of the same genetic origin have an average branch     diameter of 0.98 inches at the base of the branch. -   Branch angle: Utilizing a large protractor, the angle of each branch     was measured as its deviation from horizontal. Branch angles were     recorded for the portion of the branch emerging from the stem of the     tree with data rounded to the closest 10 degrees. ‘CF LP1-7696’ has     an average branch angle of 29.50 degrees from horizontal. Zygotic     seedlings of the same genetic origin have an average branch angle of     29.44 degrees from horizontal. -   Branch length: The length of each sampled branch was measured     directly with a graduated measurement pole. Branch lengths were     recorded to the closest 0.5 feet. ‘CF LP1-7696’ has an average     branch length of 6.48 feet. Zygotic seedlings of the same genetic     origin have an average branch length of 8.8 feet. -   Crown diameter: The width of the crown, at the point where branch     measurements were taken, was directly measured with the use of a     graduated measurement pole. A radial measurement was taken on the     East and West side of each tree. Crown radius was measured to the     closest 0.5 feet. Crown width data is presented as diameter of the     crown. ‘CF LP1-7696’ has an average crown diameter of 8.65 feet.     Zygotic seedlings of the same genetic origin have an average crown     diameter of 11.37 feet. -   Internode length: In proximity to the area of the stem utilized for     branch measurements the mean internode length was determined for     each tree. Internode distances for the calculation of the mean were     directly measured from the stem of the tree using a graduated     measurement pole. ‘CF LP1-7696’ has an average internode length of     1.22 feet. Zygotic seedlings of the same genetic origin have an     average internode length of 1.25 feet. -   Maximum trunk diameter at breast height (4.5 feet above the soil     level): 4.4 inches after 5 field growing seasons. -   Percent stem fusiform rust infection at age 5: 0. -   Percent branch fusiform rust infection at age 5: 5. -   Percent branch and stem fusiform rust infection at age 5: 0. -   Percent dead ramets due to fusiform rust infection at age 5: 0. -   Percent stem fusiform rust infection in the USDA Resistance     Screening Center (Asheville, N.C.) tests after artificial     inoculation with rust spores: 31% (compared to 76% infection in     unimproved seedlings). -   Propagation: propagated by somatic embryogenesis. -   Seeds: none produced at age 5 years of age, plants are not yet     mature. Expected seed production by 12-15 years of age. -   Use: high yield industrial plantations Although the new variety of     loblolly pine tree possesses the detailed characteristics noted     above as a result of the growing conditions prevailing in the test     locations, it is to be understood that the variations of the usual     magnitude and characteristics incident to changes in growing     conditions, irrigation, fertilization, pruning, pest control,     climatic variations and the like are to be expected. An example of     ‘CF LP1-7696’ can be found at The Campbell Group Beulah year 2003     line trial, Angelina county, Tex.

COMPARISON WITH PARENTS BY MICROSATELLITE ANALYSIS

Microsatellite markers (SSR's) were used to generate a unique DNA fingerprint for the variety. Young foliage samples from 6 ramets of LP1-7696 variety and from the parental trees used to make the LP1 cross were collected for DNA fingerprinting. The DNA extraction protocol of Doyle and Doyle (1987) was used after slight modifications. DNA fingerprinting of parents and the LP1-7696 variety was conducted using a set of nine microsatellite markers (Elsik et al., 2000; Auckland et al., 2002; Echt et al., 2008). Table 1 shows the sequences and conditions for each primer.

TABLE 1 ID's, sequences and conditions of SSR primers used in loblolly pine LP1-7696 variety. Ta = primer annealing temperature. LABEL TAIL Primer UniSTS GenBank SEQUENCE (5′-3′) (F/R); E (end  MgCl₂ full ID # accession (SEQ ID NO:) labeled) (mM) Ta (° C.) PtTX3011 508455 BV728852 F: AATTTGGGTGTATTTTTCTTAGA E 2.5 55 (SEQ ID NO: 1) R: AAAAGTTGAAGGAGTTGGTGATC (SEQ ID NO: 2) PtTX3025 508459 BV728855 F: CACGCTGTATAATAACAATCTA R 2.5 61 (SEQ ID NO: 3) R: GGATAACAATTTCACACAGG TTCTATATTCGCTTTTAGTTTC (SEQ ID NO: 4) PtTX3034 508463 BV728857 F: CACGACGTTGTAAAACGAC F 2.5 55 TCAAAATGCAAAAGACG (SEQ ID NO: 5) R: ATTAGGACTGGGGATGAT (SEQ ID NO: 6) PtTX3049 508467 BV728826 F: GAAGTGATAATGGCATAGCAAAAT E 2.5 59→ (SEQ ID NO: 7) 49 R: GCAGACCCGTGAAAGTAATAAACAT (SEQ ID NO: 8) PtTX3105 508475 BV728847 F: TGTCGGTGGAGTTGGCAGTAGACT 59→ (SEQ ID NO: 9) E 2.5 49 R: GCCCAGCGTTTCCTG (SEQ ID NO: 10) PtTX3116 508479 BV728848 F: CACGACGTTGTAAAACGAC 55→ CTCCCAAAGCCTAAAGAAT (SEQ ID F 2.5 45 NO: 11) R: CATACAAGGCCTTATCTTACAGAA (SEQ ID NO: 12) PtTX3127 508483 BV728849 F: ACCCTTACTTTCAGAAGAGGATA R 2.5 61 (SEQ ID NO: 13) R: GGATAACAATTTCACACAGG AATTGGGGTTCAACTATTCTATTA (SEQ ID NO: 14) PtSIFG_0 F: CACGACGTTGTAAAACGAC 65→ 566 516281 BV728755 ACTTAGTGGGAAAGGGGGAA (SEQ ID F 2.5 55 NO: 15) R: GTTTCTTTTCCTCAGCCAAAAGCTCTC (SEQ ID NO: 16) PtSIFG_4 F: CACGACGTTGTAAAACGAC 65→ 233 516353 BV728685 AGGGAAACCGCGGATTATAG (SEQ ID F 2.5 55 NO: 17) R: GTTTCTTCCGGAATGAAGATTGCAGTT (SEQ ID NO: 18)

Microsatellite products were detected by M13 tailed primer (Oettling et al., 1995) or infrared dye(IRD)-labeled primer. The amplification products were electrophoresed on 5.5% Long Ranger polyacrylamide gels using a LiCor 4200 automated sequencer (LiCor Inc., Lincoln, Nebr.).

The observed parental genotypes and their expected offspring's genotypes at nine studied SSR loci are presented in Table 2. LP1-7696 fingerprint based on nine loci is presented in Table 3.

TABLE 2 Parental genotypes and their expected offspring's genotypes at nine SSR loci. Genotype Primer Female Male Expected offspring genotypes PtTX3011 157/193 157/193 157/157 157/193 193/193 PtTX3025 277/289 274/277 277/274 227/227 289/274 289/277 PtTX3127 207/210 204/207 207/204 207/207 210/204 210/207 PtTX3034 228/228 216/220 228/216 228/220 PtTX3049 311/313 323/325 311/323 311/325 313/323 313/325 PtTX3116 147/150 159/180 147/159 147/180 150/159 150/180 PtTX3105 169/190 169/184 169/169 169/184 190/169 190/184 SlFG0566 133/139 145/145 133/145 139/145 SlFG4233 127/127 129/137 127/129 127/137

TABLE 3 LP1-7696 genotypes at nine SSR loci. Allelic sizes include LiCor primer tails for M13 tailed primers. PtTX3011 PtTX3025 PtTX3127 Allele1 Allele2 Allele1 Allele2 Allele1 Allele2 157 193 274 289 204 207 PtTX3034 PtTX3049 PtTX3116 Allele1 Allele2 Allele1 Allele2 Allele1 Allele2 216 228 311 325 150 180 PtTX3105 SlFG0566 SlFG4233 Allele1 Allele2 Allele1 Allele2 Allele1 Allele2 169 190 139 145 127 137

REFERENCES

-   Auckland, L., T. Bui, Y. Zhou, M. Shepherd and C. Williams. 2002.     Conifer Microsatellite Handbook Corporate Press, Raleigh, N.C., USA. -   Doyle, J. J. and J. L. Doyle. 1987. A rapid DNA isolation procedure     for small quantities of fresh tissue. Phytochemical bulletin     19:11-15. -   Echt, C. S., Saha, S. and Nelson, C. D. 2008. Southern Institute of     Forest Genetics,USDA Forest Service Southern Research Station, 23332     Mississippi 67, Saucier, Miss. 39574, USA. On-line genetic database:     http://www.ncbi.nlm.nih.gov/unists -   Elsik, C. G., Minihan, V. T., Hall, S. E., Scarpa, A. M. and     Williams, C. G. 2000. Low-copy microsatellite markers for Pinus     taeda L. Genome 43(3):550-555. -   Oetting, W. S., H. K. Lee, D. J. Flanders, G. L. Wiesner, T. A.     Sellers and R. A. King. 1995. Linkage analysis with multiplexed     short tandem repeat polymorphisms using infrared florescence and M13     tailed primers. Genomics 30:450-458. 

1. A new and distinct variety of loblolly pine tree named ‘CF LP1-7696’ substantially as described and illustrated. 